1. Field of the Invention
The present invention relates to a light source used for a projector for modulating light irradiated from a source lamp in accordance with image information to form an optical image and for enlarging and projecting the image, the light source including the source lamp, a reflector for aligning and emitting the light irradiated from the source lamp and a case for accommodating the source lamp and the reflector, and a projector provided with the source lamp.
2. Description of Related Art
Conventionally, a projector for modulating light irradiated from a source lamp in accordance with image information to form an optical image and for enlarging and projecting the image has been used.
Such projectors have been widely used for multimedia presentation in a meeting, scientific society, exhibition etc. Accordingly, in order to obtain vivid projected image by the projector, it is required for the light source to increase luminance thereof.
High-pressure mercury lamp or a metal halide lamp is used as the source lamp. When the life of the lamp expires, light-emitting tube thereof made of silica glass can be exploded to scatter the fragments around. Accordingly, the light source including the source lamp has a transparent glass plate etc. covering a light emitting surface of the reflector to prevent the fragments from scattering around even when the source lamp is exploded.
However, since the source lamp of the above-described light source is enclosed in a space defined by the reflector and the transparent glass plate, the temperature of the source lamp can become high so that the life of the source lamp can be shortened.
On the other hand, a cooling air-introducing opening may be formed on a part of the reflector and the transparent glass plate to cool the light-emitting tube. However, if an opening is formed, it is difficult to completely block the fragments from falling out when the source lamp is exploded.